A Certified Respiratory Therapist (CRT), formerly Certified Respiratory Therapy Technician (CRTT), is a therapist who has graduated from a respiratory therapy program at a university or college and has passed a national certification exam. A CRT or RRT is typically expected to adjust, modify or recommend therapeutic techniques within well-defined procedures based on a limited range of patient responses. In the healthcare setting, usually required supervision by a physician experienced in respiratory care.